The invention generally relates to insulated coils for coil and pole assemblies. More particularly, the invention relates to ground insulation for these coils.
Coil and pole assemblies normally include a magnetizing coil including of a plurality of turns of copper wire or strap which surround a magnetizable ferrous metal pole. The coil is electrically insulated from the pole with a material or materials known as ground insulation. Typically, ground insulation is applied to the coil by wrapping the coil with insulation tape. The insulation tape normally is carefully wrapped layer upon layer about the coil, inside and out, by hand. Armor tape is then wrapped about the insulation tape to provide a protective layer for the insulation tape. During this wrapping, thermally resistant strips of material such as NOMEX.RTM. brand fiber products (NOMEX is a trademark of DuPont Co.) commonly referred to as shims, are added to the top and bottom surfaces of the coil to both ensure the correct coil height and to provide the correct coil dimensions for attachment to a machine frame.
The aforementioned insulating process is time consuming and requires a large amount of manual labor. It can be appreciated that it would be advantageous to have insulation that avoids these and other problems.